Richter Scale vs Mercalli Scale
The Richter scale and Mercalli scale are based on two different methods of measuring seismic activity. This article presents the Richter scale vs Mercalli scale comparison that will give you an insight into the usage of these measurement methods.
Seismic activity occurs due to the motion of the earth’s continental crust over the underlying layers of magma.
Earthquakes, the most devastating of natural disasters, are the result of intense seismic activity. The only way of preventing large scale loss of life and property that occurs through earthquakes is creating advanced warning mechanisms or earthquake forecasting
methods. For such a purpose and recording the levels of seismic activity, Richter scale and Mercalli scale were created. In this article is presented a Richter scale vs Mercalli scale comparison that points out the major differences between these seismic activity measurement techniques.
Difference Between Richter and Mercalli Scale
To accurately describe the scale of intensity of an earthquake, a proper scientific method was developed by scientists devoted to earthquake study, who are called seismologists. There are a number of methods of measuring the intensity of an earthquake. One could measure it according to the magnitude of actual seismic energy that is released or measure it according to the intensity or effects of the earthquake on the surroundings. In fact two separate types of seismic scales exist that depend on magnitude and intensity.
The magnitude scales used to measure seismic activity all over the world are body wave magnitude scale, Richter scale, moment magnitude scale and surface wave magnitude scale. The seismic scales that are used to measure the intensity of earthquakes are European Macroseismic Scale (EMS), INQUA scale, Medvedev-Sponheuer-Karnik (MSK) scale, Shindo scale and the modified Mercalli scale. The magnitude and intensity scales used in United States of America are the Richter scale and the Mercalli scale which I’ve compared below.
Richter Scale Vs Mercalli Scale: History The Mercalli scale in its original form predates the Richter scale and has its origins in the Rossi-Forel scale used in the 19 th
century. It was modified by Giuseppe Mercalli, an Italian volcanologist between 1884 and 1906. After a host of revisions and modifications from its original form, it was given its present form by Charles Richter, the guy who also created the Richter scale of earthquake magnitude measurement. After the modifications made by Richter, it came to be known as Modified Mercalli Intensity (MMI) scale.
Inspired by the apparent magnitude scale used in astronomy to study the stars, Charles Richter, along with his associate Beno Gutenberg, created the Richter scale in 1935. It is the most widely used seismic activity measurement scale used today.
Richter Scale Vs Mercalli Scale: Definition
The Richter and Mercalli scales are different in nature. The Mercalli scale is largely subjective as it measures the intensity of earthquake, whereas Richter scale is an objective and numerical measurement based on readings taken by seismometers. There is a Richter scale formula for calculating the magnitude of earthquake from the instrument readings. The scale is logarithmic in nature.
The Modified Mercalli Scale is divided into twelve levels with each ascending level describing a graver scale of destruction. It begins with the ‘Instrumental (Level I)’ when tremors are felt only by the instruments and extends up to the highest intensity state (Level XII- called ‘Cataclysmic’) characterized by total destruction.
The Richter scale range extends from zero to excess of 10 in numerical magnitude. Minor earthquakes fall in the range from 0-3.9, moderate earthquakes from 5 to 5.9, strong earthquakes from 6 to 6.9 and most destructive earthquakes occur in the range of 7 and above. A correlation between the magnitude and intensity of an earthquake can be made by correlating the Richter scale and Modified Mercalli scale measurements.
An explanation of Mercalli scale and Richter scale for kids is best done using a chart. It is essential that earthquake safety procedures be explained to students and the general public.
This Richter scale vs Mercalli scale comparison was intended to give you an insight into how the magnitude and intensity scales differ in their measurement methods. Thanks to years of research conducted by seismologists, today we know a lot more about seismic activity and earthquakes than before. Advanced measurement techniques that use Richter and Mercalli scales have contributed a lot in advancing our knowledge about earthquake prone zones.
